The present invention relates to a machine for fitting a sleeve seal onto a container, and more particularly relates to a machine for fitting automatically a sleeve seal of a flat form onto the top of the container such as a bottle.
When a sleeve seal, which is usually a tube of heat-shrinkable film, is supplied in a collapsed form, flat like a piece of ribbon, it is quite difficult to open it up so that it can be fitted over the neck of a container and heat-shrunk thereonto. The difficulty is accentuated if the process is to be performed rapidly and repeatedly by an automatic machine.
In the prior art, such a sleeve seal has been opened up by suction cups. However, in this case, only the central part of the tube can be opened up, and the edges of the flattened seal cannot be satisfactorily stretched so as to open them up. Thus the size of the sleeve seal must be considerably larger than the neck of the container, over which it is to be fitted, and this may well mean that a tight seal cannot be attained, since the amount of shrinkage available from the film while preserving its desirable characteristics is limited.